Wellington lee tanner



Reissued Apr. 10, 1928.

UNITED STATES PATENT OFFICE,

WELLINGTON LEE TANNER, or EL MOLINO, SONORA, MEXICO, ASSIGNOR TO THE ones- SELLI CHEMICAL COMPANY, or CLEVELAND, 01110, A CORPORATION or OHIO.

PROCESS OF MAKING ARSENATES OF MANGANESE AND PRODUCT THEREOF.

No Drawing. Original No. 1,591,795, dated July 6, 1926, Serial No. 654,781, filed July 30, 1923. Renewed November 12, 1925 Application for reissue filed August 9, 1927. Serial No. 211,844.

This invention relates to insecticidal coinposltions consisting ezsentially of arsenates of manganese, and to a process of making and arsenic, manganese dioxid and arsenious oxid.

Arsenates of manganese can be made by reacting upon manganese carbonate with arsenic acid and also as I have found by reacting upon manganese monoxid with arsenic oxid or acid. I have now found that 'arscnates of manganese may be made from arsenious oxid by treating the same with a nonoxidizing compound .of manganese such as the monoxid or carbonate in the presence of an oxidizing agent such as nitric acid, or by treating the arsenious oxid with an oxidizing compound of manganese such as manganese nitrate or the higher oxide of manganese such as Mn O,, Mn' O and MnO, or mixtures thereof, the success of the last mentioned reactions presumably depending wholly, or at least in part, upon the mutual and simultaneous oxidation of the arsenious oxid to the arsenic oxid or its theoretical equivalent and the reduction of the manganese to the divalent atom. From the standpoint of economical commercial manufacture of arsenates of manganese the -'use of manganese dioxid and arsenious oxid 'of course is preferred, since these two compounds offer the cheapest and most plentiful sources of manganese and arsenic for that purpose at the present time, and the inven tion will be described and illustrated hereinafter by reference to the process of making arsenates of manganese from manganese dioxidand arsenious oxid, although it is to be understood that the invention embraces the other novel combinations of reagents l'ieretofore referred to. I

When manganese dioxid and arsenious oxid are heated together in the presence of moisture chemical combination takes place, but the reaction is either too slow'or too incomplete to suffice for the commercial use. In experimental work directed to the find binat-ion of manganesedioxid with arsenious oxid could be hastened and brought to completion or substantial completion in a commercially practicable manner, the effect of a variety of catalytic or accelerating agents was tried with varyingsuccess. The results of these experiments clearly indicated that as catalytic or accelerating agents may be used, in general, substances capable of forming an easily dlssociable or labile compound with manganese. Among substances of this general class may be mentioned nitric acid, nitrobenzene, picric acid, acetic acid, formic acid, hydrofiuosilicic acid, sulfonic acid products of hydrocarbons, and metal nitrates, such as manganese nitrate and the alkali and alkaline earth metal nitrates. is indicated therefore the use of a catalytic agent for the reaction is preferred, although, as stated, manganese dioxid and arsenious oxid react in .the absence of a catalytic agent and the carrying out of the reaction in the absence of a catalytic agent, therefore, is embraced by the invention.

Further characteristics of the invention will be pointed out hereinafter.

The following is a description of a preferred procedure in accordancewith my invention, which will serve to illustrate it.

261- parts by weight of manganese dioxid or an equivalent quantity of a .manganese dioxid containing material, such as a manganese dioxid ore, or concentrate, is mixed with 198 parts by weight of arsenious oxid (white arsenic) or an equivalent quantity of an arsenious oxid containing material, 160 parts by weight of water, and 12 parts by weight of nitric acid, and the mixture is heated to a temperature of say 80 to 100 C. in, for instance, a hot Water or steam acketcd vessel and stirred or agitated, Water being added from time to time, if necessary, to maintain the mixture in condition.

The proportions of manganese dioxid and arsenious oxid given are the theoretical combining proportions, the quantity of water is the quantity found to give the best results, both with respect to reaction rate and the workability of the mixture, the quantity of nitric acid is the best from the standpoint pf economy inthe use of nitric acid and reaction rate, and the temperature is highest ing of reaction conditions wherebythe com temperature usable Without undue evaporation of the liquid content of the mixture. Under the conditions stated, substantially complete reaction will take place in about three hours. The reaction doesnot produce a specific chemical compound of constant stolchlometric PI'OPOl'tlOIlS of manganese and arsenic, the end products of the reaction mixture is too dry, and if too much, water is used, for instance, a quantity suflicient to .makea thin slurry, the reaction rate is retarded. The quantity of nitric acid in the reaction mixture may also be varied. It, for

reaction mixture is reduced by one half, the reaction rate is greatly reduced, while the use of more nitric acid does not give a corresponding increase in the reaction rate. In general the hi her the temperature 'to which the reaction mixture is heated, the greater is the reaction rate and the carrying out of the process under superatmospheric. pressure in order to make possible the employment of higlug temperatures therefore is contemp a e Oxids, of manganese other than M110 to wit, Mn O and Mn o, or mixtures thereof may replace wholly, or in part, the manganese dioxid in the foregoin' example.

,As has already been state a variety of catalytic or accelerating agents may be used, for instance in the example, the twelve parts by weight of nitric acid may be replaced by an equal weight of nitrobenzene, the results being substantially the same as with the nitric acid. When for instance acetic acid or formic acid is substituted for the nitric acid in the example, the reaction is accelerated,

but the results are not so ood, the reaction rate being considerably s ower than when the nitric acid is used.

The product may be marketed directly in the pasty condition in which it is produced,

or it may be ground and then dried, or the paste may be dried and then ground, as preferred. lhe product in view of its arsenic content suggests itself as beinga valuable material for use as or.in insecticides. It does not burn plant foliage. Its water solubility is within the limits permissible for the application of arsen'ates tothe destruction of harmful insects on growing plants.

In the appended claims I have defined the interaction of arseiiious acid with a manganese compound. capable of oxidizing arsenious acid under which of course are ineluded manganese nitrate and the higher oxids of manganese.

It is also to be understood that the claims cover not only the use of suchoxidizing compounds of manganese as starting materials, but also the use as starting materials of reagents capable of forming or having the same effect as the oxidizing compounds of manganese such as for instance, the use of a non-oxidizing compound of i'nanganese in conjunction with an oxidizing agent.

I claim:

-1. Process of making manganese arsenatcs avliicli comprises heating to reacting temperature a mixture of a compound of manganese capable of oxidizing"arsenious oxid with arsenious oxid in the presence of water.

2. Process of making manganese arsenates which comprises heating to reacting temperature a mixture ot'a higher oxid of manganese than the monoxid with arsenious oxid i I .in the presence of water. instance, the quantity or nltrlc acid in' the 3. Process of making manganese arsenates which con'ipriscs heating to reacting temperature a mixture of a higher end of manganese than themonoxid with arsenious oxid in the presence of water and a catalytic agent.

4. Process of making manganese arsenates whichcomprises heatingto reacting temperature a mixture of a higher oxid of manganese than the monoxid with arsenious oxid in the presence of Waterand a substance capable of forming with manganese an easily dissociable product.

5. Process of makingmanganese arsenates which comprises heating to reacting temperature a mixture of a higher oxid of manganese than the monoxid with, arsenious oxid in the presence of water and nitric acid.

6. Process of making manganese arsenates which comprises heating to reacting temperature a mixture containing a higher oxid of manganese than the monoxid with arsenious oxid andwater in quantity suflicient to form a pasty mass and a catalytic agent.

7. A process as defined in claim 6 in which the catalytic agent employed is nitric acid. l

8. Process as defined in claim 6 in whicli the oxid of manganese employed is man-- 198 parts by weight of arsenious oxid, 160

parts. by weight of water and 12' parts by weight of nitric acid, agitating the mixture during the heating operation and adding water as required to maintain the consistency thereof.

10. Process of nates' which comprises heating to reacting making manganese arsetemperature a mixture of an oxy compound of man anese and arse'nious oxid in'the presence of an oxidizing agent capable of oxidizing arsenious arsenic to arsenic arsenic and water. I

11.As an insecticide, a product substantially identical with the reaction product obtainable by heating to reacting temperature in the presence of water a mixture of arsenious oxid with a compound of manganese capable of oxidizing ,arseniou's oxid, said reaction product being a complex aggregate containing a plurality of manganese compounds in various hydration stages.

12. As an insecticide, a product substantially identical with the reaction product obtainable by heating to reacting tempera ture a mixture of an oxy compound of manganese and arsenious oxid in the presence of water and of an oxidizing agentcapable of oxidizing trivalent arsenic to pentavalent arsenic, said reaction product being a com plex aggregate containing a plurality of manganese compounds in various hydration, stages.

As an insecticide, a product substam tially identical with the reaction product obtainable by heating to reacting temperature a mixture of a higher oxid of manganese than the lnonoxid with arsenious oxid in the presence of water and of a substance capable of forming with the manganese an easily dissociable product, said reactionprocluct being a complex aggregate containing a plurality of manganese compounds in various hydration stages. j

I 14. As an insecticide, a product substantially identical with the reaction product obta nable by heating to 80100 C. temperature a mixture compr'ising'about 261 parts by weight of manganese dioxide, 198 parts by weight of arsenious oxid, 160 parts by weight of water, and 12 parts by wei ht of I nitric acid, agitating the mixture uring the heating operation and adding water as required to maintain the consistency thereof, said reaction product being a complex aggregate containing a pluralityof manganese compounds in various h dration stages.

In testimony whereo ,'I aflix my signature.

WELLINGTON LEE TANNTER. 

